<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>bool</title>
</head>

<body>
    <script>
        // Boollean()转换为bool类型 有数据就是true,无数据就是false
        //alert(Boolean(2))
        var i = 10
        while (i) {
            alert(i)
            i--

        }
    </script>
</body>

</html>